Thread: Copper coated steel bundy line

Originally Posted by Tote

Fair enough, My series 1 has some copper lines but as stated they may be replacements. The line from the reservoir to the master cylinder is also copper but this would not be under pressure anyway.

Regards,
Tote

Doesn't matter if it is under pressure or not - if it breaks it will let the fluid out. Not all at once but you will still end up without brakes. And yes, that line was steel from the factory too.

pretty sure the issue with copper brake lines is work hardening from being pressure pulses as brakes are used over thousands of cycles. At least that's my recollection of how it was explained at TAFE many years ago.

I very much doubt that the pressure pulses have much to do with it - the major effect will be vibration from the movement of the vehicle over the road (especially on corrugations) and vibration from engine vibration and out of balance prop shafts and wheels. The brake pressure impulses probably are at a rate of a few per kilometre (or way less on rural roads) where vibration from engine and drive train is typically hundreds of times per minute, and from the road irregularities at a similar rate. And the strain from both of these is likely to be higher than the strain due to pressure, and more importantly, is concentrated at particular spots, such as the base of the flare at each end.

Pipes are supposed to be secured to prevent vibration, but even so, there is some scope for movement, and securing is often neglected when pipes are replaced.